#ifndef _RenderOperation_H__
#define _RenderOperation_H__


#include "U2PreRequest.h"
#include "U2VertexIndexData.h"


U2EG_NAMESPACE_BEGIN


/** 'New' rendering operation using vertex buffers. */
class _U2Private U2RenderOperation
{
public:
	/// The rendering operation type to perform
	enum OperationType {
		/// A list of points, 1 vertex per point
        OT_POINT_LIST = 1,
		/// A list of lines, 2 vertices per line
        OT_LINE_LIST = 2,
		/// A strip of connected lines, 1 vertex per line plus 1 start vertex
        OT_LINE_STRIP = 3,
		/// A list of triangles, 3 vertices per triangle
        OT_TRIANGLE_LIST = 4,
		/// A strip of triangles, 3 vertices for the first triangle, and 1 per triangle after that 
        OT_TRIANGLE_STRIP = 5,
		/// A fan of triangles, 3 vertices for the first triangle, and 1 per triangle after that
        OT_TRIANGLE_FAN = 6
    };

	/// Vertex source data
	U2VertexData *vertexData;

	/// The type of operation to perform
	OperationType operationType;

	/** Specifies whether to use indexes to determine the vertices to use as input. If false, the vertices are
	 simply read in sequence to define the primitives. If true, indexes are used instead to identify vertices
	 anywhere in the buffer, and allowing vertices to be used more than once.
   	 If true, then the indexBuffer, indexStart and numIndexes properties must be valid. */
	bool useIndexes;

	/// Index data - only valid if useIndexes is true
	U2IndexData *indexData;

    // ##########################################
	/// Debug pointer back to renderable which created this
	//const Renderable* srcRenderable;

    /// The number of instances for the render operation - this option is supported 
    /// in only a part of the render systems.
    size_t numberOfInstances;

    /// a flag to indicate that it is possible for this operation to use a global
    /// vertex instance buffer if available. 
    bool useGlobalInstancingVertexBufferIsAvailable;



    U2RenderOperation() 
        : vertexData(0)
        , operationType(OT_TRIANGLE_LIST)
        , useIndexes(true)
        , indexData(0)
        /*, srcRenderable(0)*/ 
        , numberOfInstances(1)
        , useGlobalInstancingVertexBufferIsAvailable(true)
    {}


};


U2EG_NAMESPACE_END


#endif
